Analysis & Opinion

BEIJING/WASHINGTON (Reuters) - A fresh roster of U.S. and Chinese economic and diplomatic officials on Wednesday pledged to strengthen relations between the world's two largest economies, even as concerns persist over currency rates, cybersecurity and the Korean peninsula.

U.S. Treasury Secretary Jack Lew, in his first international trip since taking office last month, wrapped up a two-day visit to Beijing with a meeting with Chinese Premier Li Keqiang, having reopened dialogue on economic reforms but saying more action is needed on China's exchange rate.

"It was clear from the discussions that China has made a serious commitment to their reform agenda. The challenge will be to drive forward toward material progress," Lew told reporters shortly before heading back to Washington.

On economic reforms, Lew said the dominant theme "was what can be done to generate more domestic demand and more growth."

Li told Lew that Sino-U.S. relations should establish "a new form of thinking" and that both sides should use a "strategic, global and long-term vision to view each other," according to a Chinese government website.

Separately, Chinese Foreign Minister Wang Yi told U.S. Secretary of State John Kerry in a phone call on Wednesday that Sino-U.S. relations are "now at a new historical point, we have to forge ahead on the foundations set by the previous people," the Chinese government said.

A senior U.S. official said Kerry, congratulating Wang on his new post, spoke with him about the secretary of state's planned trip to China next month, as well as bilateral and regional issues, North Korea, and cybersecurity.

Like Kerry and Lew, Wang and Li are both newly appointed to their positions.

The exchanges this week offer a preview of deeper talks scheduled for later this year when both Kerry and Lew will host their Chinese counterparts in Washington for the U.S-China Strategic and Economic Dialogue, an annual high-level forum.

COMPETITION AND COOPERATION

Underscoring the continued economic friction between Washington and Beijing, a bipartisan group of U.S. lawmakers on Wednesday reintroduced legislation to pressure China to allow its currency to rise further against the dollar. Similar proposals in recent years have failed to make it into law.

Many lawmakers assert that China's yuan is undervalued, harming U.S. exporters.

The yuan has appreciated 16 percent in real terms against the dollar since June 2010. The currency hit an all-time high against the dollar on Wednesday, but Lew said China needs to make more progress reforming its foreign exchange regime.

"China's exchange rate should be market-determined. That's in our interest and China's interest. They recognize the need to do it for internal reasons as well," Lew told reporters.

Lew's visit with China's new leaders and senior economic officials as well as with U.S. business leaders in Beijing was aimed at improving economic cooperation and boosting growth.

The two sides also discussed growing tensions on the Korean peninsula, European debt, Internet security and climate change.

Li, who was chosen as premier on Friday, told Lew that China "is ready to work with the United States to promote Sino-U.S. relations and develop it in a cooperative, inclusive, healthy and stable way amid competition," the government said.

During his talks, Lew raised the issue of computer hacking. U.S. President Barack Obama last week convened a meeting with CEOs at the White House on such digital attacks and later called Xi over the issue.

The concerns follow a recent assessment by U.S. intelligence leaders that for the first time said cyber attacks and cyber espionage had supplanted terrorism as the nation's top threat.

"It has to be recognized, as the president indicated, this is a very serious threat to our economic interests. There was no mistaking how seriously we take this issue," Lew told reporters.

On North Korea, which has made a series of provocative threats, Lew said the United States and China "will continue to pursue methods available to change the policy perspective in Pyongyang. We share a common objective of a denuclearized Korean peninsula and we will continue to discuss it."

(Corrects family name for Chinese premier to Li from Keqiang, paragraph 5)